#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,i=1,b[10]={0},s=0,t=1;
	cin>>a;
	{
		if(a==0)
		{
			cout<<i<<":0";
			return 0;
		}
		while(a)
		b[i]=a%10,a/=10,i++;
		cout<<i-1<<":";
		for(int j=1;j<=i-1;j++)
		cout<<b[j];
	}	
    return 0;
}
